<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>

<body>
  <div id="root">
    <div>文字: {{a.b.c}}</div>
    <div>输入框： <input type="text" v-model="a.b.c"></div>
    {{b}}
  </div>
</body>

</html>